Processes for producing aerosol propellants that include butane or isobutane

ABSTRACT

The invention relates to the discovery of compositions useful as aerosol propellants that include a first component of butane or isobutane and a second component of 2-fluoropropane (HFC-281 ea) or 1-fluoropropane (HFC-282 fa).

RELATIONSHIP TO OTHER APPLICATIONS

This application is a Continuation-In-Part of Ser. No. 08/541,055,filing date Oct. 11, 1995 now U.S. Pat. No. 5,681,501.

FIELD OF THE INVENTION

This invention relates to compositions that include ahydrofluoropropane. These compositions are useful as refrigerants,cleaning agents, expansion agents for polyolefins and polyurethanes,aerosol propellants, refrigerants, heat transfer media, gaseousdielectrics, fire extinguishing agents, power cycle working fluids,polymerization media, particulate removal fluids, carrier fluids,buffing abrasive agents, and displacement drying agents.

BACKGROUND OF THE INVENTION

Fluorinated hydrocarbons have many uses, one of which is as arefrigerant. Such refrigerants include trichlorofluoromethane (CFC-11)and chlorodifluoromethane (HCFC-22).

In recent years it has been pointed out that certain kinds offluorinated hydrocarbon refrigerants released into the atmosphere mayadversely affect the stratospheric ozone layer. Although thisproposition has not yet been completely established, there is a movementtoward the control of the use and the production of certainchlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) under aninternational agreement.

Accordingly, there is a demand for the development of refrigerants thathave a lower ozone depletion potential than existing refrigerants whilestill achieving an acceptable performance in refrigeration applications.Hydrofluorocarbons (HFCs) have been suggested as replacements for CFCsand HCFCs since HFCs have no chlorine and therefore have zero ozonedepletion potential.

In refrigeration applications, a refrigerant is often lost duringoperation through leaks in shaft seals, hose connections, solderedjoints and broken lines. In addition, the refrigerant may be released tothe atmosphere during maintenance procedures on refrigeration equipment.If the refrigerant is not a pure component or an azeotropic orazeotrope-like composition, the refrigerant composition may change whenleaked or discharged to the atmosphere from the refrigeration equipment.The change in refrigerant composition may cause the refrigerant tobecome flammable or to have poor refrigeration performance.

Accordingly, it is desirable to use as a refrigerant a singlefluorinated hydrocarbon or an azeotropic or azeotrope-like compositionthat includes one or more fluorinated hydrocarbons.

Fluorinated hydrocarbons may also be used as cleaning agents or solventto clean, for example, electronic circuit boards. It is desirable thatthe cleaning agents be azeotropic or azeotrope-like because in vapordegreasing operations the cleaning agent is generally redistilled andreused for final rinse cleaning.

Azeotropic or azeotrope-like compositions that include a fluorinatedhydrocarbon are also useful as blowing agents in the manufacture ofclosed-cell polyurethane, phenolic and thermoplastic foams, aspropellants in aerosols, as heat transfer media, gaseous dielectrics,fire extinguishing agents or power cycle working fluids such as for heatpumps. These compositions may also be used as inert media forpolymerization reactions, fluids for removing particulates from metalsurfaces, as carrier fluids that may be used, for example, to place afine film of lubricant on metal parts or as buffing abrasive agents toremove buffing abrasive compounds from polished surfaces such as metal.They are also used as displacement drying agents for removing water,such as from jewelry or metal parts, as resist developers inconventional circuit manufacturing techniques including chlorine-typedeveloping agents, or as strippers for photoresists when used with, forexample, a chlorohydrocarbon such as 1,1,1-trichloroethane ortrichloroethylene.

SUMMARY OF THE INVENTION

The present invention relates to the discovery of compositions whichinclude a first component of tetrafluoropropane, trifluoropropane,difluoropropane or fluoropropane and a second component oftetrafluoropropane, trifluoropropane, difluoropropane, fluoropropane and1,1,1-trifluoro-2-trifluoromethylpropane, a hydrocarbon ordimethylether. These compositions are useful as refrigerants, cleaningagents, expansion agents for polyolefins and polyurethanes, aerosolpropellants, heat transfer media, gaseous dielectrics, fireextinguishing agents, power cycle working fluids, polymerization media,particulate removal fluids, carrier fluids, buffing abrasive agents, anddisplacement drying agents.

Further, the invention relates to the discovery of binary azeotropic orazeotrope-like compositions comprising effective amounts oftetrafluoropropane, trifluoropropane, difluoropropane or fluoropropaneand a second component of tetrafluoropropane, trifluoropropane,difluoropropane, fluoropropane and1,1,1-trifluoro-2-trifluoromethylpropane, a hydrocarbon ordimethylether, to form an azeotropic or azeotrope-like composition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-254ca and HFC-263fb at 25° C.;

FIG. 2 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-254ca and HFC-272ca at 25° C.;

FIG. 3 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-254ca and HFC-356mmz at 25° C.;

FIG. 4 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-254ca and HFC-butane at 25° C.;

FIG. 5 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-254ca and cyclopropane at 25° C.;

FIG. 6 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-254ca and isobutane at 25° C.;

FIG. 7 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-254ca and propane at 25° C.;

FIG. 8 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-254cb and 254eb at 25° C.;

FIG. 9 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-254cb and HFC-272ca at 25° C.;

FIG. 10 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-254cb and HFC-281fa at 25° C.;

FIG. 11 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-254cb and butane at 25° C.;

FIG. 12 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-254cb and cyclopropane at 25° C.;

FIG. 13 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-254cb and isobutane at 25° C.;

FIG. 14 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-254eb and HFC-272ca at 25° C.;

FIG. 15 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-254eb and HFC-281fa at 25° C.;

FIG. 16 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-254eb and butane at 25° C.;

FIG. 17 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-254eb and cyclopropane at 25° C.;

FIG. 18 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-254eb and isobutane at 25° C.;

FIG. 19 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-263ca and HFC-356 mmz;

FIG. 20 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-263ca and butane;

FIG. 21 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-263ca and isobutane;

FIG. 22 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-263fb and HFC-272ea;

FIG. 23 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-263fb and HFC-281ea;

FIG. 24 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-263fb and HFC-281fa;

FIG. 25 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-263fb and DME;

FIG. 26 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-263fb and isobutane;

FIG. 27 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-272ca and HFC-272ea;

FIG. 28 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-272ca and HFC-281fa;

FIG. 29 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-272ca and butane;

FIG. 30 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-272ea and HFC-356 mmz;

FIG. 31 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-272ea and butane;

FIG. 32 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-272ea and cyclopropane;

FIG. 33 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-272ea and isobutane;

FIG. 34 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-272fb and butane at;

FIG. 35 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-281ea and butane -9.95° C.;

FIG. 36 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-281ea and isobutane -9.95° C.;

FIG. 37 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-281fa and butane; and

FIG. 38 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-281fa and isobutane.

DETAILED DESCRIPTION

The present invention relates to the following compositions:

(a) 1,2,2,3-tetrafluoropropane (HFC-254ca) and 1,1,1-trifluoropropane(HFC-263fb); HFC-254ca and 2,2-difluoropropane (HFC-272ca); HFC-254caand 1,1,1-trifluoro-2-trifluoromethyl propane (HFC-356 mmz); HFC-254caand butane; HFC-254ca and cyclopropane; HFC-254ca and isobutane; orHFC-254ca and propane;

(b) 1,1,2,2-tetrafluoropropane (HFC-254cb) and1,1,1,2-tetrafluoropropane (HFC-254eb); HFC-254cb and2,2-difluoropropane (HFC-272ca); HFC-254cb and 1-fluoropropane(HFC-281fa); HFC-254cb and butane; HFC-254cb and cyclopropane; orHFC-254cb and isobutane;

(c) 1,1,1,2-tetrafluoropropane (HFC-254eb) and 2,2-difluoropropane(HFC-272ca); HFC-254eb and 1-fluoropropane (HFC-281fa); HFC-254eb andbutane; HFC-254eb and cyclopropane; or HFC-254eb and isobutane;

(d) 1,2,2-trifluoropropane (HFC-263ca) and1,1,1-trifluoro-2-trifluoromethyl propane (HFC-356 mmz); HFC-263ca andbutane; or HFC-263ca and isobutane;

(e) 1,1,1-trifluoropropane (HFC-263fb) and 1,2-difluoropropane(HFC-272ea); HFC-263fb and 2-fluoropropane (HFC-281ea); HFC-263fb and1-fluoropropane (HFC-281fa); HFC-263fb and dimethyl ether (DME); orHFC-263fb and isobutane;

(f) 2,2-difluoropropane (HFC-272ca) and 1,2-difluoropropane (HFC-272ea);HFC-272ca and 1-fluoropropane (HFC-281fa); or HFC-272ca and butane;

(g) 1,2-difluoropropane (HFC-272ea) and1,1,1-trifluoro-2-trifluoromethyl propane (HFC-356 mmz); HFC-272ea andbutane; HFC-272ea and cyclopropane; or HFC-272ea and isobutane;

(h) 1,1-difluoropropane (HFC-272fb) and butane;

(i) 2-fluoropropane (HFC-281ea) and butane; or HFC-281ea and isobutane;or

(j) 1-fluoropropane (HFC-281fa) and butane; HFC-281fa and isobutane.

1-99 wt. % of each of the components of the compositions are useful asrefrigerants, cleaning agents, expansion agents for polyolefins andpolyurethanes, aerosol propellants, refrigerants, heat transfer media,gaseous dielectrics, fire extinguishing agents, power cycle workingfluids, polymerization media, particulate removal fluids, carrierfluids, buffing abrasive agents, and displacement drying agents.Further, the present invention also relates to the discovery ofazeotropic or azeotrope-like compositions of effective amounts of eachof the above mixtures to form an azeotropic or azeotrope-likecomposition.

By "azeotropic" composition is meant a constant boiling liquid admixtureof two or more substances that behaves as a single substance. One way tocharacterize an azeotropic composition is that the vapor produced bypartial evaporation or distillation of the liquid has the samecomposition as the liquid from which it was evaporated or distilled,that is, the admixture distills/refluxes without compositional change.Constant boiling compositions are characterized as azeotropic becausethey exhibit either a maximum or minimum boiling point, as compared withthat of the non-azeotropic mixtures of the same components.

By "azeotrope-like" composition is meant a constant boiling, orsubstantially constant boiling, liquid admixture of two or moresubstances that behaves as a single substance. One way to characterizean azeotrope-like composition is that the vapor produced by partialevaporation or distillation of the liquid has substantially the samecomposition as the liquid from which it was evaporated or distilled,that is, the admixture distills/refluxes without substantial compositionchange. Another way to characterize an azeotrope-like composition isthat the bubble point vapor pressure and the dew point vapor pressure ofthe composition at a particular temperature are substantially the same.

It is recognized in the art that a composition is azeotrope-like if,after 50 weight percent of the composition is removed such as byevaporation or boiling off, the difference in vapor pressure between theoriginal composition and the composition remaining after 50 weightpercent of the original composition has been removed is less than about10 percent, when measured in absolute units. By absolute units, it ismeant measurements of pressure and, for example, psia, atmospheres,bars, torr, dynes per square centimeter, millimeters of mercury, inchesof water and other equivalent terms well known in the art. If anazeotrope is present, there is no difference in vapor pressure betweenthe original composition and the composition remaining after 50 weightpercent of the original composition has been removed.

Therefore, included in this invention are compositions of effectiveamounts of:

(a) HFC-254ca and HFC-263fb; HFC-254ca and HFC-272ca; HFC-254ca andHFC-356 mmz; HFC-254ca and butane; HFC-254ca and cyclopropane; HFC-254caand isobutane; or HFC-254ca and propane;

(b) HFC-254cb and HFC-254eb; HFC-254cb and HFC-272ca; HFC-254cb andHFC-281fa; HFC-254cb and butane; HFC-254cb and cyclopropane; orHFC-254cb and isobutane;

(c) HFC-254eb and HFC-272ca; HFC-254eb and HFC-281fa; HFC-254eb andbutane; HFC-254eb and cyclopropane; or HFC-254eb and isobutane;

(d) HFC-263ca and HFC-356 mmz; HFC-263ca and butane; or HFC-263ca andisobutane;

(e) HFC-263fb and HFC-272ea; HFC-263fb and HFC-281ea; HFC-263fb andHFC-281fa; HFC-263fb and DME; or HFC-263fb and isobutane;

(f) HFC-272ca and HFC-272ea; HFC-272ca and HFC-281fa; or HFC-272ca andbutane;

(g) HFC-272ea and HFC-356 mmz; HFC-272ea and butane; HFC-272ea andcyclopropane; or HFC-272ea and isobutane;

(h) HFC-272fb and butane;

(i) HFC-281ea and butane; or HFC-281ea and isobutane; or

(j) HFC-281fa and butane; HFC-281fa and isobutane;

such that after 50 weight percent of an original composition isevaporated or boiled off to produce a remaining composition, thedifference in the vapor pressure between the original composition andthe remaining composition is 10 percent or less.

For compositions that are azeotropic, there is usually some range ofcompositions around the azeotrope point that, for a maximum boilingazeotrope, have boiling points at a particular pressure higher than thepure components of the composition at that pressure and have vaporpressures at a particular temperature lower than the pure components ofthe composition at that temperature, and that, for a minimum boilingazeotrope, have boiling points at a particular pressure lower than thepure components of the composition at that pressure and have vaporpressures at a particular temperature higher than the pure components ofthe composition at that temperature. Boiling temperatures and vaporpressures above or below that of the pure components are caused byunexpected intermolecular forces between and among the molecules of thecompositions, which can be a combination of repulsive and attractiveforces such as van der Waals forces and hydrogen bonding.

The range of compositions that have a maximum or minimum boiling pointat a particular pressure, or a maximum or minimum vapor pressure at aparticular temperature, may or may not be coextensive with the range ofcompositions that have a change in vapor pressure of less than about 10%when 50 weight percent of the composition is evaporated. In those caseswhere the range of compositions that have maximum or minimum boilingtemperatures at a particular pressure, or maximum or minimum vaporpressures at a particular temperature, are broader than the range ofcompositions that have a change in vapor pressure of less than about 10%when 50 weight percent of the composition is evaporated, the unexpectedintermolecular forces are nonetheless believed important in that therefrigerant compositions having those forces that are not substantiallyconstant boiling may exhibit unexpected increases in the capacity orefficiency versus the components of the refrigerant composition.

The components of the compositions of this invention have the followingvapor pressures at the temperature specified.

    ______________________________________                                                    25° C.                                                                             -9.95° C.                                      COMPONENTS    PSIA    KPA       PSIA KPA                                      ______________________________________                                        HFC-254ca     13.7     94                                                     HFC-254cb     34.2    236                                                     HFC-254eb     34.8    240                                                     HFC-263ca     18.2    125                                                     HFC-263fb     54.0    372                                                     HFC-272ca     34.5    238                                                     HFC-272ea     20.8    143                                                     HFC-272fb     26.5    183                                                     HFC-281ea     47.1    325       14.2 98                                       HFC-281fa     37.7    260                                                     HFC-356mmz    16.6    114                                                     butane        35.2    243       10.2 70                                       cyclopropane  105.0   724                                                     isobutane     50.5    348       15.8 109                                      propane       137.8   950                                                     DME           85.7    591                                                     ______________________________________                                    

Substantially constant boiling, azeotropic or azeotrope-likecompositions of this invention comprise the following (all compositionsare measured at 25° C.):

    ______________________________________                                                       WEIGHT RANGES PREFERRED                                        COMPONENTS     (wt. %/wt/%)  (wt. %/wt. %)                                    ______________________________________                                        HFC-254ca/HFC-263fb                                                                          1-36/64-99    1-36/64-99                                       HFC-254ca/HFC-272ca                                                                          1-52/48-99    1-52/48-99                                       HFC-254ca/HFC-356mmz                                                                         1-79/21-99    1-79/21-99                                       HFC-254ca/butane                                                                             1-65/35-99    1-65/35-99                                       HFC-254ca/cyclopropane                                                                       1-51/49-99    1-51/49-99                                       HFC-254ca/isobutane                                                                          1-60/40-99    1-60/40-99                                       HFC-254ca/propane                                                                            1-53/47-99    1-53/47-99                                       HFC-254cb/HFC-254eb                                                                          1-99/1-99     20-80/20-80                                      HFC-254cb/HFC-272ca                                                                          1-99/1-99     20-80/20-80                                      HFC-254cb/HFC-281fa                                                                          1-99/1-99     1-60/40-99                                       HFC-254cb/butane                                                                             1-99/1-99     40-99/1-60                                       HFC-254cb/cyclopropane                                                                       1-60/40-99    1-60/40-99                                       HFC-254cb/isobutane                                                                          1-80/20-99    1-80/20-99                                       HFC-254eb/HFC-272ca                                                                          1-99/1-99     20-80/20-80                                      HFC-254eb/HFC-281fa                                                                          1-99/1-99     20-99/1-80                                       HFC-254eb/butane                                                                             1-99/1-99     20-99/1-80                                       HFC-254eb/cyclopropane                                                                       1-59/41-99    1-59/41-99                                       HFC-254eb/isobutane                                                                          1-82/18-99    1-82/18-99                                       HFC-263ca/HFC-356mmz                                                                         1-99/1-99     20-80/20-80                                      HFC-263ca/butane                                                                             1-67/33-99    1-67/33-99                                       HFC-263ca/isobutane                                                                          1-56/44-99    1-56/44-99                                       HFC-263fb/HFC-272ea                                                                          66-99/1-34    66-99/1-34                                       HFC-263fb/HFC-281ea                                                                          1-99/1-99     40-99/1-60                                       HFC-263fb/HFC-281fa                                                                          1-99/1-99     40-99/1-60                                       HFC-263fb/DME  1-83/17-99    1-83/17-99                                       HFC-263fb/isobutane                                                                          1-99/1-99     40-99/1-60                                       HFC-272ca/HFC-272ea                                                                          41-99/1-59    41-99/1-59                                       HFC-272ca/HFC-281fa                                                                          1-99/1-99     20-80/20-80                                      HFC-272ca/butane                                                                             1-99/1-99     40-99/1-60                                       HFC-272ea/HFC-356mmz                                                                         10-99/1-90    20-80/20-80                                      HFC-272ea/butane                                                                             1-64/36-99    1-64/36-99                                       HFC-272ea/cyclopropane                                                                       1-42/58-99    1-42/58-99                                       HFC-272ea/isobutane                                                                          1-55/45-99    1-55/45-99                                       HFC-272fb/butane                                                                             1-99/1-99     20-99/1-80                                       HFC-281ea/butane                                                                             1-99/1-99     20-99/1-80                                       HFC-281ea/isobutane                                                                          1-99/1-99     20-99/1-80                                       HFC-281fa/butane                                                                             1-99/1-99     20-99/1-80                                       HFC-281fa/isobutane                                                                          1-99/1-99     10-99/1-90                                       ______________________________________                                    

For purposes of this invention, "effective amount" is defined as theamount of each component of the inventive compositions which, whencombined, results in the formation of an azeotropic or azeotrope-likecomposition. This definition includes the amounts of each component,which amounts may vary depending on the pressure applied to thecomposition so long as the azeotropic or azeotrope-like compositionscontinue to exist at the different pressures, but with possibledifferent boiling points.

Therefore, effective amount includes the amounts, such as may beexpressed in weight percentages, of each component of the compositionsof the instant invention which form azeotropic or azeotrope-likecompositions at temperatures or pressures other than as describedherein.

For the purposes of this discussion, azeotropic or constant-boiling isintended to mean also essentially azeotropic or essentially-constantboiling. In other words, included within the meaning of these terms arenot only the true azeotropes described above, but also othercompositions containing the same components in different proportions,which are true azeotropes at other temperatures and pressures, as wellas those equivalent compositions which are part of the same azeotropicsystem and are azeotrope-like in their properties. As is well recognizedin this art, there is a range of compositions which contain the samecomponents as the azeotrope, which will not only exhibit essentiallyequivalent properties for refrigeration and other applications, butwhich will also exhibit essentially equivalent properties to the trueazeotropic composition in terms of constant boiling characteristics ortendency not to segregate or fractionate on boiling.

It is possible to characterize, in effect, a constant boiling admixturewhich may appear under many guises, depending upon the conditionschosen, by any of several criteria:

The composition can be defined as an azeotrope of A, B, C (and D . . . )since the very term "azeotrope" is at once both definitive andlimitative, and requires that effective amounts of A, B, C (and D . . .) for this unique composition of matter which is a constant boilingcomposition.

It is well known by those skilled in the art, that, at differentpressures, the composition of a given azeotrope will vary at least tosome degree, and changes in pressure will also change, at least to somedegree, the boiling point temperature. Thus, an azeotrope of A, B, C(and D . . . ) represents a unique type of relationship but with avariable composition which depends on temperature and/or pressure.Therefore, compositional ranges, rather than fixed compositions, areoften used to define azeotropes.

The composition can be defined as a particular weight percentrelationship or mole percent relationship of A, B, C (and D . . . ),while recognizing that such specific values point out only oneparticular relationship and that in actuality, a series of suchrelationships, represented by A, B, C (and D . . . ) actually exist fora given azeotrope, varied by the influence of pressure.

An azeotrope of A, B, C (and D . . . ) can be characterized by definingthe compositions as an azeotrope characterized by a boiling point at agiven pressure, thus giving identifying characteristics without undulylimiting the scope of the invention by a specific numerical composition,which is limited by and is only as accurate as the analytical equipmentavailable.

The azeotrope or azeotrope-like compositions of the present inventioncan be prepared by any convenient method including mixing or combiningthe desired amounts. A preferred method is to weigh the desiredcomponent amounts and thereafter combine them in an appropriatecontainer.

Specific examples illustrating the invention are given below. Unlessotherwise stated therein, all percentages are by weight. It is to beunderstood that these examples are merely illustrative and in no way areto be interpreted as limiting the scope of the invention.

EXAMPLE 1 Phase Study

A phase study shows the following compositions are azeotropic, all at25° C.

    ______________________________________                                                                   Vapor Press.                                       Composition No.            psia (kPa)                                         ______________________________________                                        HFC-254ca/HFC-263fb                                                                            5.0/95.0  54.4    375                                        HFC-254ca/HFC-272ca                                                                           18.1/81.9  36.5    252                                        HFC-254ca/HFC-356mmz                                                                          26.5/73.5  20.5    141                                        HFC-254ca/butane                                                                              34.4/65.6  41.5    286                                        HFC-254ca/cyclopropane                                                                         9.3/90.7  106.5   734                                        HFC-254ca/isobutane                                                                           25.5/74.5  55.6    383                                        HFC-254ca/propane                                                                              6.6/93.4  138.7   956                                        HFC-254cb/HFC-254eb                                                                           55.5/44.5  30.3    209                                        HFC-254cb/HFC-272ca                                                                           55.2/44.8  37.6    259                                        HFC-254cb/HFC-281fa                                                                           17.2/82.8  38.0    262                                        HFC-254cb/butane                                                                              63.0/37.0  45.6    314                                        HFC-254cb/cyclopropane                                                                         8.1/91.9  105.3   726                                        HFC-254cb/isobutane                                                                           46.2/53.8  57.0    393                                        HFC-254eb/HFC-272ca                                                                           54.9/45.1  38.1    263                                        HFC-254eb/HFC-281fa                                                                           39.2/60.8  38.2    263                                        HFC-254eb/butane                                                                              62.9/37.1  44.8    309                                        HFC-254eb/cyclopropane                                                                         5.5/94.5  105.2   725                                        HFC-254eb/isobutane                                                                           44.7/55.3  56.2    387                                        HFC-263ca/HFC-356mmz                                                                          42.3/57.7  19.8    137                                        HFC-263ca/butane                                                                              26.4/73.6  36.9    254                                        HFC-263ca/isobutane                                                                            8.6/91.4  50.7    350                                        HFC-263fb/HFC-272ea                                                                           94.2/5.8   54.8    378                                        HFC-263fb/HFC-281ea                                                                           79.3/20.7  56.6    390                                        HFC-263fb/HFC-281fa                                                                           89.8/10.2  55.2    381                                        HFC-263fb/DME   42.4/57.6  90.2    622                                        HFC-263fb/isobutane                                                                           69.1/30.9  58.3    402                                        HFC-272ca/HFC-272ea                                                                           81.7/18.3  37.0    255                                        HFC-272ca/HFC-281fa                                                                           52.2/47.8  40.2    277                                        HFC-272ca/butane                                                                              53.6/46.4  36.9    254                                        HFC-272ea/HFC-356mmz                                                                          36.6/63.4  24.0    165                                        HFC-272ea/butane                                                                              32.2/67.8  40.6    280                                        HFC-272ea/cyclopropane                                                                         3.8/96.2  105.3   726                                        HFC-272ea/isobutane                                                                           20.9/79.1  54.0    372                                        HFC-272fb/butane                                                                              33.0/67.0  36.9    254                                        HFC-281fa/butane                                                                              53.8/46.2  42.6    294                                        HFC-281fa/isobutane                                                                           26.4/73.6  53.2    367                                        ______________________________________                                    

A phase study showed the following compositions are azeotropic at -9.95°C.:

    ______________________________________                                        HFC-281ea/butane                                                                            72.9/29.1    15.2   105                                         HFC-281ea/isobutane                                                                         44.7/55.3    18.1   125                                         ______________________________________                                    

EXAMPLE 2 Impact of Vapor Leakage on Vapor Pressure at 25° C.

A vessel is charged with an initial composition at 25° C., and the vaporpressure of the composition is measured. The composition is allowed toleak from the vessel, while the temperature is held constant at 25° C.,until 50 weight percent of the initial composition is removed, at whichtime the vapor pressure of the composition remaining in the vessel ismeasured. The results are summarized below.

    ______________________________________                                                      0 wt %    50 wt %                                               Refrigerant   evaporated                                                                              evaporated                                                                              0% change in                                Composition   psia (kPa)                                                                              psia (kPa)                                                                              vapor pressure                              ______________________________________                                        HFC-254ca/HFC-263fb                                                            5.0/95.0     54.4   375    54.4 375  0.0                                       1/99        54.2   374    54.1 373  0.2                                       36/64       50.9   351    46.0 317  9.6                                       37/63       50.7   350    45.5 314  10.3                                    HFC-254ca/HFC-272ca                                                           18.1/81.9     36.5   252    36.5 252  0.0                                       1/99        34.9   241    34.6 239  0.9                                       40/60       35.7   246    34.5 238  3.4                                       50/50       34.7   239    31.8 219  8.4                                       52/48       34.5   238    31.1 214  9.9                                     HFC-254ca/HFC-356mmz                                                          26.5/73.5     20.5   141    20.5 141  0.0                                       10/90       19.9   137    18.9 130  5.0                                       1/99        17.4   120    16.7 115  4.0                                       50/50       19.8   137    19.0 131  4.0                                       70/30       18.1   125    16.4 113  9.4                                       79/21       17.0   117    15.3 105  10.0                                    HFC-254ca/butane                                                              34.4/65.6     41.5   286    41.5 286  0.0                                       20/80       41.3   285    40.1 276  2.9                                       13/87       40.8   281    36.9 254  9.6                                     ______________________________________                                    

The results of this Example show that these compositions are azeotropicor azeotrope-like because when 50 wt. % of an original composition isremoved, the vapor pressure of the remaining composition is within about10% of the vapor pressure of the original composition, at a temperatureof 25° C.

EXAMPLE 3 Impact of Vapor Leakage at 50° C.

A leak test is performed on compositions of HFC-272ca and HFC-272ea, atthe temperature of 50° C. The results are summarized below.

    ______________________________________                                        Refrigerant   0 wt %    50 wt %                                               Composition   evaporated                                                                              evaporated                                                                              0% change in                                HFC-272ca and HFC-272ea                                                                     psia (kPa)                                                                              psia (kPa)                                                                              vapor pressure                              ______________________________________                                        80.0/20.0     75.4   592    75.4 592  0.0                                       99/1        71.0   490    70.5 486  0.7                                       60/40       73.5   507    71.8 495  2.3                                       40/60       68.1   470    62.6 432  8.1                                       34/66       65.8   454    59.3 409  9.9                                       33/67       65.4   451    58.7 405  10.2                                    ______________________________________                                    

These results show that compositions of HFC-272ca and HFC-272ea areazeotropic or azeotrope-like at different temperatures, but that theweight percents of the components vary as the temperature is changed.

EXAMPLE 4 Refrigerant Performance

The following table shows the performance of various refrigerants. Thedata are based on the following conditions.

    ______________________________________                                        Evaporator temperature                                                                             45° F. (7.0° C.)                           Condenser temperature                                                                             130° F. (54.0° C.)                          Return gas temperature                                                                             65° F. (18.0° C.)                          Subcool temperature  15° F. (-9.0° C.)                          Compressor efficiency is                                                                           75%                                                      ______________________________________                                        Refrig.                                                                       Comp.                                                                         HFC-                                                                          254ca/ Evap.     Cond.     Comp. Dis.   Capacity                              HFC-   Press.    Press.    Temp.        BTU/min                               263fb  Psia (kPa)                                                                              Psia (kPa)                                                                              ° F. (° C.)                                                             COP  (kw)                                  ______________________________________                                         1/99  30.0   207    119.0                                                                              820  155.0                                                                              68.3 3.53 127.7                                                                              2.2                        99/1    6.9    48     35.9                                                                              248  161.3                                                                              71.8 3.79  39.0                                                                              0.7                        ______________________________________                                    

EXAMPLE 5

This Example is directed to measurements of the liquid/vapor equilibriumcurves for the mixtures in FIGS. 1-38.

Turning to FIG. 1, the upper curve represents the composition of theliquid, and the lower curve represents the composition of the vapor.

The data for the compositions of the liquid in FIG. 1 are obtained asfollows. A stainless steel cylinder is evacuated, and a weighed amountof HFC-254ca is added to the cylinder. The cylinder is cooled to reducethe vapor pressure of HFC-254ca, and then a weighed amount of HFC-263fbis added to the cylinder. The cylinder is agitated to mix the HFC-254caand HFC-263fb, and then the cylinder is placed in a constant temperaturebath until the temperature comes to equilibrium at 25° C., at which timethe vapor pressure of the HFC-254ca and HFC-263fb in the cylinder ismeasured. Additional samples of liquid are measured the same way, andthe results are plotted in FIG. 1.

The curve which shows the composition of the vapor is calculated usingan ideal gas equation of state.

Vapor/liquid equilibrium data are obtained in the same way for themixtures shown in FIGS. 2-38.

The data in FIGS. 1-7, 9-34 show that at 25° C., there are ranges ofcompositions that have vapor pressures higher than the vapor pressuresof the pure components of the composition at that same temperature. Asstated earlier, the higher than expected pressures of these compositionsmay result in an unexpected increase in the refrigeration capacity andefficiency for these compositions versus the pure components of thecompositions.

The data in FIGS. 35 and 36 show that at -9.95° C. there are ranges ofcompositions that have vapor pressures higher than the vapor pressuresof the pure components of the composition at that same temperature.

The data in FIG. 8 show that at 25° C., there are ranges of compositionsthat have vapor pressures lower than the vapor pressures of the purecomponents of the composition at that same temperature.

The novel compositions of this invention, including the azeotropic orazeotrope-like compositions, may be used to produce refrigeration bycondensing the compositions and thereafter evaporating the condensate inthe vicinity of a body to be cooled. The novel compositions may also beused to produce heat by condensing the refrigerant in the vicinity ofthe body to be heated and thereafter evaporating the refrigerant.

In addition to refrigeration applications, the novel constant boiling orsubstantially constant boiling compositions of the invention are alsouseful as aerosol propellants, heat transfer media, gaseous dielectrics,fire extinguishing agents, expansion agents for polyolefins andpolyurethanes and power cycle working fluids.

ADDITIONAL COMPOUNDS

Other components, such as aliphatic hydrocarbons having a boiling pointof -60 to +100° C., hydrofluorocarbonalkanes having a boiling point of-60 to +100° C., hydrofluoropropanes having a boiling point of between-60 to +100° C., hydrocarbon esters having a boiling point between -60to +100° C., hydrochlorofluorocarbons having a boiling point between -60to +100° C., hydrofluorocarbons having a boiling point of -60 to +100°C., hydrochlorocarbons having a boiling point between -60 to +100° C.,chlorocarbons and perfluorinated compounds, can be added to theazeotropic or azeotrope-like compositions described above withoutsubstantially changing the properties thereof, including the constantboiling behavior, of the compositions.

Additives such as lubricants, corrosion inhibitors, surfactants,stabilizers, dyes and other appropriate materials may be added to thenovel compositions of the invention for a variety of purposes providedthey do not have an adverse influence on the composition for itsintended application. Preferred lubricants include esters having amolecular weight greater than 250.

I claim:
 1. A process for producing a propellant composition for use with aerosols, which comprises using the composition consisting essentially of the following compounds in amounts effective to form a binary azeotrope or azeotrope-like composition having a vapor pressure at 25° C. higher than that of each compound of the binary composition:a. 1-50 weight percent 1-fluoropropane and 50-99 weight percent isobutane, and b. 10-99 weight percent 1-fluoropropane and 1-90 weight percent butane.
 2. A process as in claim 1 wherein said binary azeotrope or azeotrope-like composition consists of 1-50 weight percent 1-fluoropropane and 50-99 weight percent isobutane.
 3. A process as in claim 1 wherein said binary azeotrope or azeotrope-like composition consists of 10-99 weight percent 1-fluoropropane and 1-90 weight percent butane. 